In 1956, Arthur Kornberg and his colleagues identified DNA polymerase I in Escherichia coli, an
achievement that earned Kornberg the Nobel Prize in Physiology or medicine in 1959. Over the
years, research revealed that DNA polymerases are not a singular entity but a diverse family of
enzymes, each with specialized functions.
DNA polymerase builds new DNA strands by adding nucleotides to an existing chain. During cell
division, DNA polymerase makes sure each new cell gets accurate copy of the genetic code, and
during DNA repair, where it helps fix errors. Many DNA polymerases also check for mistakes as they
add new building blocks, ensuring that our genetic information remains correct.
DNA polymerase is tightly controlled. It works mainly during the S-phase of the cell cycle. Helper
proteins like sliding clamps keep it attached to DNA. Chemical modifications such as phosphorylation
adjust its activity. The availability of nucleotides also affects its function.
DNA polymerase is key in many technologies. It drives PCR to amplify small amounts of DNA. It helps
decode genetic information in sequencing. It is used for cloning and mutagenesis in genetic
engineering. It also aids studies of DNA repair.